Conventional furrow openers and grain drills typically include two round and flat steel disks mounted to a drawbar for the purposes of creating a seedbed. Double disk furrow openers and grain drills are either of a conventional design or a min-till design. The double disks on a furrow opener of a conventional design downwardly converge relative to each other to establish a common pinch point or area toward a forward end thereof. While downwardly conveying toward each other, the double disks on a furrow opener of a min-till design are mounted in a fore-and-aft staggered relation relative to each other and have a different angular orientation relative to each other than are the disks of a furrow opener of a conventional design. The min-till design of grain drill is typically used when less soil preparation has been done and for soil conservation purposes.
A variety of soil consistencies may be encountered during a planting operation. Under certain conditions, dirt, mud, trash, and the like tends to cling or adhere to the inside faces of the disk. Removing soil clinging to the inside surfaces of the disks is particularly difficult in heavy clay soil and most difficult when planting is done when such soil is wet. With the enhanced mechanization of farming operations and the increased speed at which the implements are drawn across a field, this problem has become acute and, in many types of soil, has rendered the use of double disk furrow openers virtually impractical.
Accumulations of dirt can stop the turning of the disks, which renders them ineffective for proper opening of furrows for seeding. Improper or uneven removal of clods of soil from between the disks can cause other problems, such as uneven planting depths. The disk cleaning problem is further aggravated in those grain drill furrow openers wherein the disks are poorly manufactured and have other than a completely flat surface across the entirety thereof. The angular differences between disks used on a conventional grain drill and those used on a min-till furrow opener further complicates the problem of removing accumulated dirt from between the disks.
Different scraper designs have been proposed for removing dirt accumulations from inner faces of the disk. Some of the scraper designs, however, fail under heavy stripping requirements. Moreover, the heretofore known scraper designs are not typically interchangeable between conventional and min-till type furrow openers. Accordingly, a farmer is burdened by having to keep a parts inventory for those scrapers used on conventional type furrow openers plus a scraper parts inventory for the min-till type furrow openers.
Misadjustment in centering the heretofore known scrapers between the disks of the furrow openers presents another problem. As will be appreciated, a centering misadjustment of the scrapers between the double disks often causes a scraper to wipe or clean one disk more effectively than the cleaning action offered to the other disk. The need to exactly center the scraper mechanism between the disks of the furrow opener, of course, adds time and expense to repair and maintenance procedures.
Other scraper designs include a pair of scraper blades resiliently biased outwardly under the influence of a spring so as to offer a self-adjusting capability for the scraper. Resiliently urging the scraper blades against the inner surface of the disks advantageously solves the misalignment problem of heretofore known scraper designs by allowing the scraper blades to "float". Constant contact of the scraper blades against the inner faces of the furrow opener disks, however, causes wear and noise problems on many of the scraper designs. The addition of the spring element to such a scraper design furthermore adds cost to the assembly.
Thus, there is a need and a desire for a furrow opener scraper assembly which is consistent and reliable in moist, heavy clay soil conditions and yet is economical to manufacture and easy to install and service on both conventional and min-till furrow opener designs.